To Starspeaker shippers: Fatespeaker is technically a hybrid, or at least a teeny-tiny bit IceWing, because she has the silver scales of a moonborn or maybe a nearly-moonborn. Anyway, she has silver scales, which means she was descended from Whiteout, who, as some people have already said, is a hybrid. Just putting it out there.
I think hybrids are able to produce dragonets. Darkstalker, Sunny, Ah! That's all the hybrids I remember so far. Sunny, for example is both NightWing and SandWing. That's probably why some of her actions aren't like other SandWings. Oh Moons! I have a theory! If Sunnyflight is going to be cannon, then who is that NightWing saying thanks to her father. Starflight is the father. Sunny can also create a full NightWing. Why? Because she has the genes of a NightWing as well as a SandWing's.